Currently, there is increased interest in energy efficiency and in decreasing environmental pollution, leading to increased demand for the development of an environmentally-friendly vehicle that can substantially replace an internal combustion engine vehicle. Such an environmentally-friendly vehicle may be classified as an electric vehicle that is driven using a fuel cell or electricity as a power source, or as a hybrid vehicle that is driven using an engine and an electric battery.
An electric vehicle using a fuel cell converts the chemical reaction energy of oxygen and hydrogen to electrical energy to produce driving torque, and in this process, thermal energy is produced by the chemical reaction within the fuel cell. To preserve the performance of the fuel cell, it is essential to effectively remove the generated heat.
Similarly, a hybrid vehicle generates driving torque by driving a motor using electricity supplied from an electric battery or a fuel cell combined with an engine operating with a general fuel, and it is essential to effectively remove heat from the fuel cell, battery, and motor to preserve the performance of the fuel cell, battery, and motor.
Such a hybrid vehicle is operated in an electric vehicle (“EV”) mode driven by a motor upon constant-speed driving, gentle driving, and low and medium constant-speed driving. Upon acceleration and rapid acceleration, an internal combustion engine and a motor are simultaneously driven, and upon high constant-speed driving, the motor is stopped and the hybrid vehicle is operated by the internal combustion engine.
Accordingly, a hybrid vehicle includes an engine cooling means for circulating and cooling coolant in an engine and an electrical equipment cooling means for circulating and cooling coolant in an electric power component including a motor.
However, in such a conventional hybrid vehicle, the engine cooling means, the electrical equipment cooling means, and an air conditioner for cooling and heating an interior of the vehicle are each formed with a separate closed and sealed circuit. This creates problems because a cooling module provided at the front side of the vehicle to supply a refrigerant or coolant to each means becomes complex and also the weight and the size increase.
To prevent interference with other components, the length of connection pipes connecting each means to a cooling module may increase to be longer than a necessary length. Smooth operation of each means may become difficult because resistance occurs due to the increased movement distance of the operation fluids.
As the maximum load conditions for the cooling means and the air conditioner are different, optimized control of each means is difficult and this deteriorates the efficiency and performance of each means. Power consumption also increases because of the increased operating time of a cooling fan and thus the entire fuel consumption of a vehicle increases.
Further, when the weight and size of a cooling module increase, it is difficult to secure sufficient collision space at the front side of the vehicle and thus there is a problem that collision safety regulations are not satisfied.
The above information disclosed in this Background section is only for enhancing the understanding of the background of the disclosure and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.